Indophenol sulfonic acids and process of making same.



UNTTED STATT$ PATENT OFFIGE.

AUGUST L'EOPOLD LASKA, O11 ()FFICNBAUll-ON Tl*llG-MA1N, GERMANY,

ASSIGNOR TO THE FIRM ()F K. ()EHLER, ANILIN- 8a ANILINFARBEN- FABRIK, OF ()FFENBAGl'l-()N-lllllG-M;\lN, (,lrlCRMANY.

INDOPHENOL SULFONIC ACIDS AND PROCESS OF MAKING SAME.

Specification of Letters Patent.

Patented Sept. 5, 1905.

Application filed April 13,1905. Serial No. 265,472. (Specimens) 1'0 ('r Z/ whom it 7111151 colt/writ:

Be it known that l, AUoUs'r Lnoeom) L \sk.\, doctor of philosophy, chemist, residing at 5 (lerberstrasse, (j)lfeubach-mr-the-Main, in the Grand Duchy of .llesse, (lei-many, have invented certain new and useful Improvements in lndophenol Sulfonie Acids, of which the following is a specilication.

My invention relates to the production of new indophenol sulfonic acids, which are distinguished from other indophenol bodies by their fair stability. These new indophenol sulfonic acids can be obtained by simultaneously oxidizing in an alkaline solution paraphenylendiamin sulfonic acid and a phenol. They represent very important initial materials in the manufacture of sulfur dyes.

The following example will serve to illustrate the manner in which my invention may be best carried out. Dissolve fortwseven parts of para-phenylendiamin sulfonic acid and 27.2 parts of meta-cresol in live hundred parts of water and seventy parts of soda-lye, (35 Baun1e,)cool with ice, and oxidize by means of sodium hypochhin'ite corresponding to eight parts real oxygen. Hereby the temperature may rise to +5 Centigrade without essentially altering the result. The solution becomes bluish violet. On addition of common salt the indophenol sulfonic acid separates as a precipitate with a metallic luster in a practically quantitative yield. A fter liltersuits, which dissolves in water to a bluish violet, turning into a pure blue on adding conentiat lso dium-lye and into a blackish blue on addition of diluted hydrochloric acid. concentrated sulfuric acid theindophenol sulfonic acid dissolves with a yellowish green color. Sodium sullid yields the lightyellow solution of the diphenylamin derivate. The corresponding indophenol sulfonic acid from ortho-cresol is formed in a similar manner. lts aqueous solution is some redder and is also changed to blue by concentrated sodium-Lye.

The indophenol sulfonic acid from phenol is distinguisl'ied by its exceedingly easy solubility and may be precipitated from the pure blue oxidation liquid, but with dil'liculty.

The indophenol sulfonic acid, obtainable in the manner above described from alpha-oxynaphtoie acid. dissolves in water with a claret red, being in its behavior very like to the bet'ore-mentioned indophenol sulfonic acids.

instead of sodium hypochlorite other oxidizing means acting in alkaline solutions in equimolecular proportions may be employed.

.Now what I claim, and desire to secure by Letters Patent, is the following:

1. The process of making indophenol sulfonic acids. consisting in simultaneously oxidizing para-phenylendiamin sulfonic acid and a phenol.

2. The process of making indophenol sulfonic acids, consisting in simultaneously oxidizing in an alkaline solution para-phenylendiamin sulfonic acid and a phenol.

3. new articles, the indophenol sulfonie acids which are obtained by simultaneously oxidizing in an alkaline solution para-phenylendiamin sulfonic acid and a phenol, and which, in the form of their sodiumsalt in a dry state, represent a black-brown powder, dissolve in water to a bluish-violet solution, being rendered somewhat bluer on adding sodium-lye, and changing into a blackish blue,

; while simultaneously precipitating the indoing and drying at black1.sh-l )rown powder rephenol sulfonic acid, on addition of hydrochloric acid, all substantially as hereinbefore described.

In testimony that I claim the foregoing as my invention 1 have signed my name, in presence of two witnesses, this 31st day of March, 1905.

AUG UST LEOPOLD LASKA.

\Vitnesses:

lllGR'MANN Winn, llmNmou Nnunxuaw'r. 

